...
Mail loops are when an email sent from JEMHC ends up back in finds its way back into a JEMHC mailbox. This is bad because undesirable as it consumes your capacity plan Plan allowance for no useful outcome.
Consequences of mail loops
...
Identifying mail from loops
All JEMHC mail is ‘tagged’ with a header notification email includes a Precedence: bulk header, which by default JEMHC will block on the way in. This action stop the loop and prevents it from creating a comment/update updates that would trigger a further notification - such a case would be a runaway loop - JEMHC detects and blocks that. This consumes a message from your Plan allowance. You can find these problem messages via JEMHC > Auditing > Inbound Messages, then view the source Jira issue to see where this comes from and fix. 
| Info |
|---|
Set Operation: Precedence Bulk on the Inbound Messages screen to filter to |
...
view messages where this header was detected and blocked |
Example Auditing output:
...
Example Report from audit entry
...